Photoelectric device



April 24, 1945. D. E. HENRY PHOTOELECTRIC DEVICE Filed Nov. 19, 1941 2 Sheets-Sheet l INVENTOR p. E. lff/VEY ATTORNEY April 24, 1945. D. E. HENRY PHOTOELECTRIC DEVICE Fil ed Nov. 19, 1941 2 Sheets-Sheet 2' l lfl l l l l l n u u Ilka vuh n u qfllx W a u. L a J a 15.9 INVENTOR .D. E: .fi'E/VE Y W ATTORNEY Patented Apr. 24, 1945 PHOTOELECTRIC DEVICE Donald E. Henry, Cedar Grove, N.IJ.. assi'grio'r to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application November 19, 1941, Serial No. 419,667

- 16 Claims. (01. 2505165) This invention relates to photo-electric-devices and, mo e particularly, to such adapted to record radiations from all directions above the cathode plane.

The principal object of my invention, generally considered, is to provide a photo-electric tube with a light-sensitive cathode in the form of a flat plate, said cathode being sensitizable from an electrode normally disposed inwardly thereof when swung to inoperative position, and means for swinging the same after sensitization so as to face outwardly and co-operate with an operating anode.

Another object of my invention is the provision of a photo-electric tube having a flat cathode adapted to swing parallel to an electrode in the form of a Wire or rod of metal for sensitizing the surface of said cathode, and then swing outwardly for co-operation with another electrode.

A further object of my invention is the provision of a photo-electric tube consisting of a sensitized cathode having a fiat surface, and means for localizing the sensitizing film on the cathode lead portions which are disposed relatively remote from the radiation to be measured.

A still further object of my invention is the provision of a photo-electric tube with a hinged cathode, whereby said cathode may be sensitized when in one position and then moved to operative position by tipping the bulb, with means for locking said cathode in operative position.

An additional object of my invention is the provision of a photo-electric tube with a hinged cathode which is movable from one position to another, whereby it may be activated in one position by sputtering from an inwardly disposed electrode formed of a material to be used as the sensitizing agent and then moved to operative position for co-operation with an operating anode.

Another object of my invention is the provision of a photo-electric tube having a cathode in the form of a flat plate movable from sensitizing to operating positions, a shield carried in the enclosing envelope to protect the cathode leads adjacent the operative position of the cathode, and another shield for shading the supporting press to protect the leads from short-circuits.

Other objects and advantages of the invention, relating to the particular arrangement and construction of various parts, will become apparent as thedescription proceeds.

Referring to the drawings Figure 1 is an elevational view of a photo-electrics tube embodying my invention.

. Figure 2'is a perspective view of the upper portion of the tube shown in Figure 1 with portions broken away- Figure '3 is an enlarged sectional view of the upper portion of the tube on theline II IIII of Figure 1, in the direction of the arrows.

Figure 4 is a sectional view on the line IV-IV of Figure 3, in the direction of the arrows.

Figure 5 is a fragmentary view showing a portion of, the tube illustrated in Figure 1, but with the light sensitive cathode in position to be activated.

Figure 6 is a perspective view corresponding to Figure 2, but showing a modification.

Figure '7 is an axial sectional view of the upper portion of the tube shown in Figure 6, with the cathode in operativeposition.

Figure 8 is a view corresponding to Figure '7, but showing the cathode reversed with respect to the tube and the whole device transposed into position to be activated or sensitized.

Figure 9 is an enlarged perspective view of the cathode stop, arrangement.

Figure 10 is a small scale view showing one of my phototubes finished by application of an extension cord. and protective tape.

The cathode of a phototube, for recording radiations from all directions above its plane,

should not be obstructed in any way, as by a shield,base, or vaporized or sputtered material,

which would interfere with radiation falling on the sensitized surface. For long continued measurements such a tube should be very stable.

In accordance with my invention I have provided a phototube in which a metal plate to form the cathode thereof is arranged to face, and preferably hang parallel to, the rod or wire of sensitive-material to be sputtered thereon during the sensitizing operation, at the same time making it possible to localize the deposit on the cathode leads toward the lower part of the tube, or relatively remote from the operative position of the cathode. This type of construction also lends itself better to the sensitizing of the cathode by vaporizing material from an oxide-coated filament or electrode, in which process the sensitivity must be tested frequently by shining a light on the cathode after or during the depositing.

Referring. now to the drawings in detail, and

first consideringthe embodiment of my invention illustrated in Figures 1 to 5, inclusive, there is shown a phototube ll provided with an envelope l2 desirably composed of amaterial such as Corning No. 974, high transmission ultra-violet glass if the tube is tomeasure ultra-violet radiations. If the tube is to measure other than ultraviolet radiations, it is, of course, formed of material pervious to the type of radiations to be measured. Other materials suitable for the transmission of ultra-violet radiations are quartz, high silica glass, Corning No. 791 and Corex glass. For measuring the radiations inthe bactericidal range, Corning No. 972 glass is particularly appropriate and the tube of the present embodiment is especially adapted for that purpose.

Within the main or upper portion of the en'- velope I2 is provided a press l3 on which is mounted a rod-shaped electrode I4. This elec-.

trode may be composed of titanium, if 1 the. tube is to be used like that of the Rentschler' Patent #1,955,608 of April 17, 1934, for the measurement of ultra-violet radiations between about 2500 and 3200 Angstrom unitsfor for the meas- 38 and 31, and connected by bracing wire 38 also forming a stop for the hinge member 32 of the plate I9.

That portion of the reinforcing ring 33 remote from the angular plate 32 has secured thereto a keeper member comprising a plate 39 depending therefrom and having a notch 4| to receive the flanged or angular end portion 42 of a spring latch 43. To the latch is secured an iron armature 44, adapted for operation by an external magnet 45, shown dotted in Figure 1.

The latch 43 is supported on a bracing wire 46,

urement of such in sunlight between 3200 A. U. r

and the atmospheric cut-off. If, however, the tube is to be used for the measurement-of bactericidal radiations, or those having wave lengths of 3000 Angstrom units and shorter, then I preferably employ tantalum as the material forming the electrode I4. The electrode H, which is used to supply the photo-sensitive material is, therefore, subject to change in accordance with the type of radiations to be measured. Thus it may be formed of zirconium, vanadium, tungsten, uranium, or other photo-electric material, if the tube is to be used for measuring radiations of other wave lengths.

The electrode I4 is mounted upon a lead-in conductor I5 extending through the press I3 to an external conductor H5. The conductor is desirably enclosed in a dielectric shield member I'| constructed of glass or similar material. The upper portion of the shield member I], and the joint between the electrode I4 and the lead-in conductor I5 is also desirably enclosed in a shield member I8, preferably formed of lavite or similar insulating material fitting the member l1 and having an aperture in its upper end through which the electrode I4 extends, thereby restricting the active area of said electrode to the exposed end portion which for this reason is the only part of the electrode that need be formed of titanium or the photo-electric material selected. I

The active portion of the cathode comprises a film of titanium or other photo-electric material. Such a film is desirably deposited upon an electrical conductor, preferably formed as a sheet of nickel I9 which is electrically connected to leading-in conductor passing'through the press I3, as illustrated. a

A framework, consisting of two parallel longitu'dinally extending wires 2| and 22 and a bracing cross wire 23, is mounted above the press I3, as by means of a carrying collar 24, frictionally engaging the flare tube 25' on which the press I3 is formed, as by being clamped thereon by means of a bolt 26 and nut 21, the former of which passes through overlapping flanges 28 and 29 on said collar. I V

Movably supported on said framework, as by means of an angular plate 32, is a preferably circular flat nickel sheet I9 carrying a sensitive cathode surface 3|. One flange of the plate 32 is secured to a circular reinforcing ring 33 on the plate I9 and the other flange is apertured as indicated at 34 and 35, to receive the wires 2| and 22, thereby providing a hinged-connec tion therebetween. The upper or free ends'oi said wires are bentoutwardly, as indicated at which extends between two longitudinally extending wires 41 and 48, desirably supported from the same carrying collar 24 as the wires 2| and 22. The upper or free end portions of said wires are bent toward one another and then extended generally parallel while disposed close together, thereby providing a guide for the keeper member '39, as indicated at 49 and 50. The ends of said wires are desirably connected by a stop wire, indicated at 5|. The cathode plate I9 is, therefore, movable from the position shown in Figure 2, as upon release of the latch 43 by the magnet 45 shown in Figure 1, to swing and slide down the wires 2| and 22 until stopped by the bracing wire 52 and bracing plate 53, where it then hangs parallel to the electrode I4, with its normally outer surface facing towards said electrode for application of the sensitive surfacing 3|. Bracing wires 60, including insulating bead 10, also desirably connect the wire 52 to the wires 41 and 48. The plate 53 also functions as a shield to prevent sensitizing the keeper 39.

The electrode to function a an anode for association with the cathode I9 is, in the present embodiment, formed as a pair of arc-shaped fine wires 54 and 55 with their ends supported from the upper circular member 58 of a wire frame 5'| consisting of wires 58 and 59 respectively extending longitudinally from a lead GI and a spud 62, projecting from the press I3 and with their upper ends bent outwardly, as indicated respectively at 63 and 64, and secured to the lower ends of the wires 58 and 59, respectively, portions of the wires 58 and 59 adjacent the ring 56 having curved wire sections 64 and 66, respectively, secured thereto. The adjacent ends of said wires 65 and 66, opposite to that where the latch member 43 is located, are desirably braced together as by means of short wires 81 and 88 welded thereto and projecting therefrom, with their adjacent ends imbedded in a glass connector 69.

The wires 58 and 59 also desirably serve to support a plate forming a shield therebetween, as by means of welds I2 and I3 at the engaging points, whereby material being sputtered from the electrode I4 is prevented from getting on the cathode leads adjacent the normal position of the cathode as shown in Figure 2. A plate forming a shield 14, desirably carrying an angular shield 80, is desirably supported from the spud 62, as by means of connecting wire I5, thereby shading the press, preventing a short-circuiting deposit of sputtered material thereon, and preventing a possible contamination of the sput- 5 tered coating by the insulator I8.

-- is allowed, with the latch 43 releasedby the magnet 45, as indicated in Figure 1, and the phototube in the position illustrated in the figures,

. to slide from the position shown in Figures 1 to ,4; inclusive, to where it lies parallel and close to the activating electrode I4, that is, from the full to the dotted line position of Figure 1. The whole is then baked out and exhausted in the usual manner heretofore employed to obtain high vacua, with the parts degasified by heat produced by high frequency induction, for example. A filling of a gaseous medium such as argon, neon or helium, preferably argon at a pressure of from 1 to 6 mm., is then introduced intothe envelope in any desired manner, as through the exhaust tube 16. The envelope is then sealed off as indicated at 11. A glow discharge is then produced to effect positive ion bombardment of the electrode I4 from the electrode I9, with a sputtering or electrical vaporization of the material or titanium of the electrode I 4 to the sheet I9 of nickel, until a uniform cathode surface having the proper spectral sensitivity is formed.

A direct current discharge is employed, with the rod I4 serving as a cathode and the sheet I9 of nickel as the anode for the discharge. In this instance the connection to the cathode may be effected by lead-in conductor 18 connecting with brace wire 52 by means of conductor 19. Temporary connection with this lead-in conductor is desirably efiected in the present instance by having an internally threaded socket 8| in the outer end of said conductor 18 with which a correspondingly threaded current carrying lead 82 may be joined in the outstanding tube 83. l

I find it preferable tocontinue the discharge for about twenty hours, the exact length of time depending upon conditions. The-sputtered material, other than that deposited upon the sheet of nickel I9, mainly collects on the shields II and 14 and the glass of the envelope between the planes of said shields, as well as the leading-in conductor and brace wires in that neighborhood. The shield 14 so covers or shades" the press I3 that clear glass areas are maintained between the lead-in conductors, thereby preventing shortcircuits therebetween. On account of the remoteness from the spherical end portion 84 of the envelope I2, no deposit is produced which would tend to absorb the radiations to be measured.

After the cathode I9 has been coated with the sputtered sensitizing material, the envelope I2 is reversed, allowing the plate I9 to slide backto the ends of the wires 2| and 22 and swing to the position illustrated in Figures 2, 3 and 4, the latch 43 being moved outwardly and springing back into the locking notch 4|, as shown in Figures 1 to 4, inclusive, thereby holding the now sensitized cathode I 9 in operative position.

The main portion 85 of the envelope I2 may then be finally exhausted, wtihout opening to the atmosphere, by a method formerly used. If argun was used as a gas filling, said main portion desirably had apparatus connected to it, like the tube 28 shown in Patent #2, 1 '7,777, dated August 1, 1939, and could be finally exhausted by means of activated charcoal in liquid air to'make a vacuum phototube and finally tipped off as indicated at 86.

If desired, a relay tube 81 and condenser 88 may be housed in the neck or extension 89 of the envelope I 2, as illustrated most clearly in Figure 1, in a manner as described and claimed in Patent #2242383, dated May 20, 1941. The relay tube 81 is desirably formed as described and claimed in Patent #2879362; dated May 4, 1937,

except that itisnot neoessa'ry to base it. That is, 'the tube comprises an envelope 9I of glass or the like and three electrodes supportedfromthe flare tube 92 thereof, the electrode 93 being desirably formed of thorium. and functioning as a cathode, electrode 94 as a main anode and electrode '95 as a starting or auxiliary anode.

Although all of these electrodes are supported from the stem or press 92 as by means of support wires 98, 91 and 98, the starting anode 95 has its outside connection desirably made by means of lead-in conductor 99 extending from the end portionof the'envelope 81 opposite to that to which-the flare tube 92 is secured. Before sealing the relay tube 81 and the condenser 88 intothe extension 89, both are desirably coated with insulating material I8I, such as-the seal. ing wax shown, in order to preventsurface leakage. As alternatives, the envelope 9| of the relay tube 81 may be painted with a light-absorbing coating or formed of red or green glass, .which is sufficiently light-absorbing, as the thorium cathode is not photo-sensitive. to wave lengths much longer than 3658A U1, while the other parts from which theleads extend are coated with sealing wax or other insulating material.

The condenser and relay tube do not have to be covered with sealing wax if the leakage during calibration is negligible, as moisture due to sealing-in can be removed duringthe exhaust.

The connections between the electrodes 14,, I9 and the anode wires 54 and 55 in the phototube compartment proper and the leads to the. relay tube and condenser in the extension or auxiliary tube 89 are as shown in Figure 1. The cathode I9 is connected by means of lead-in conductor 28, coil spring I82 and lead I83 to the lead I84 which connects one pole of the condenser 88,. to the lead-in conductor 99 from the starting anode 95. The other pole of the condenser is connected by means of lead I85 to cathode 93 and a lead I86 from said connection extends through flare or press I81 of extension 89 out of. the envelope I2, forming one of the terminals of the combination photo-tube illustrated in Figure 1.

Another terminal of the tube connects with the "mainanode 94 of the relay tube 81 by means of lead I 88 extending through the same press, I81, while the third terminal connects with the anode wires 54 and 55 of the photo-electric tube proper through supportingwires 58'and 59, lead 68, coil spring I89 and lead I-II through the same press After the main 'portion 85 of the envelope I2 has been finally exhausted-and before the relay tube 81 and condenser 88 are inserted, the leads '83 and I8 are connected together, as'by welding at H2, so that the single lead III connects with boththe activating electrode I4 and the anode wires 54 and 55. Such a connection is desirable to make it impossible for the electrode I4 to act as a photo-electric cathode, and permissible be cause said electrode is supposed to be inoperative and never used after the cathode I9 has been activated and disposed in the position shown in Figure 2. When the cathode I9 is being activated from the activating electrode I4 functioning as. a

cathode, the anode wires 54 and 55 are not ener- 55 of the radiation-responsive device disclosed are, when assembled for use, as diagrammatically shown in Figure 4 of-Patent #22 3 refe ed to, connected through lead III, and that-desig- :nated GZ-in-Said figure, tO-the positive telini'nll oLasource of potential; forexamplaabattery oi cells there designated 53. ,The negative-terminal of said; source of. potential connectedv bymeans of a lead, there designated 60, to oneside of condenser 80 through lead I06, while theother side is connected to the cathode I by meansof leads I04,,I0,3 and 20, as well as the starting anode 85 0f the relay tube by means of leads I04 and 99. The cathode 93 of the glowrelay tubed'l is'also connected to said negative pole of the battery by means of conductors I05, -I-06,..and lead designated 60 in said patent, thereby completing the input circuit to said relay tube 81 in accordance with Patent #2,037,925,.previously referred to.:,. Theoutput circuit of the system is alsoshown in Figure-4 of Patent #23 2 previously-referred to'yand comprises a fixed or variable resistance',v there: designated, 64, .of appropriate value; having one end thereof. 'connected to; the positive "terminal of one of the cells of thebattery, there designated 63, andthe other end oi which is connected to one terminal of-a record: ing device, there designated 65,- and one pole ofa condenser, there designated 66. The other pole of the condenser is connected to the negative pole of the battery, one pole of the other condenser 88 and the cathode 93 of the relay tube. The, other terminal of the recording device is connectedto the anode 04 of the :relay tube 8'I, as by means of lead-in conductor, designated in Figure ,4 ofjsaid patent by the reference character-.59, "through lead I08. a Fromthe foregoing disclosure it: willbe seen thatall the parts of.the input circuit shown in the diagram of said Figure 4,-except the energizing battery, areenclosed in. the. extendeduevacuated envelope portion 89, andthereby kept moisture-free and protected from leakage. The operation of the device for measuring radiations isas described and claimed in the Rentschler Patent #2,037,925, previously referred tov except that, by virtue of enclosingthe parts of the input circuit for protection against leakage due to moisture, the accuracy of the measurement is greatly increased. I

It will be seen that the mainrdifference in the photo-electric portion of the combined device is that the lead from the cathode I9, goes through the stem or lower part of the .envelopeportionBS, rather than throughthe upperportiom- In order, however, to test the-photo-electric portion ofthe device separately from the associated condenser 88 and relay tube 81, after the parts-are assembled as a unit, I desirably also providejalead I8 extending through the side of the enveloperportion 85, and having ascrew-threaded socket .8I,. for making a temporary connection therewith by means of the wire 82:.havingja screw-threaded inner end portion. That portion of the lead 1,8 between the seal H3 and the {connecting wire .19 is desirably a coil of soft wire II 4to, prevent strain in said seal and allow the lead 18160 be properly positioned when sealing-in. 1 After testing the photo-electric portion, the lead 82,may beiunscrewed and the tubular extension;83 closedofi, as by sealing the end in-a flame, ,topreventsurface leakage.

In manufacturing a combined meter device, such ,as heretofore disclosed, the photo-electric tube portion 85 is exhausted, the argon admitted, the electrode I4 sputtered to provide the sensitive cathode surface, and the envelope re-exhausted, as previously described. ,The-tubeisthen tested .for...the spectral positioneofgthe energy cutoff,

after which it may be exposed to radiations from a suitable sourcewith the lead 20 connected to the; top of the relay tube 81 in a regular meter circuit and the lead 63 connected to the positive side of a battery. Arrangements should be made so that the condenser 88 between the top of the relay tube 81 and the negative side of the battery can be changed at will, until one is found of such capacity that the energy unit indicating clicks of therecorder, designated 65 in, Figure 4 of Patent #239,483, previously referred to, come at the desired intervals. 1

When a condenser having the proper capacity is found, it and the relay tube are mounted on the fiare llll, as shown in Figure 1. Springs I02 and l09- are welded to the leads 20 and I6--63, respectively, coming from the photo-electric portion, in such a manner that the ends can be pulledxpast the end of the extended envelope portion 89. The relay tube 81 and condenser 88, mounted on the flare I01, using supporting spuds H5 and H6 for the relay tube 81, are pushed up into the portion 39, but the flare held far enough out so that the springs I02 and I09 can be pulled down .and respectively welded to the leads I03 and III. Positions; in making the foregoing assembly areillustrated in Figures 5 and 6 of the Patent #2,242,483,. which is again referred to for a complete description of the manner of assembly.

Referring now to the embodiment of my invention illustrated in Figures'fi, '7, 8 and 9, there is shown a phototube I I provided with an envelope IZ desirably composed of material like the envelope I2} of the. preceding embodiment. Within the main or upper portion of the envelope IZa, if a combined device is being made, I provide a press. 13 on which is mounted a rod-shaped electrode I6 composed of .material like the electrode IA of the preceding embodiment. Said electrode-isflmounted upon a lead-in conductor I5 extending through thelpress I3 to an external conductor lfi The conductor I5=- is desirably enclosed ina dielectric shield member IT, as in th preceding embodiment. The upper portion of the shield .member and the joint between the electrode M and the lead-in conductor I5 are also desirably enclosed in ashield member I8, preferably formed of lavite or similar insulating materiaL as in the preceding embodiment.

.The active portion of the cathode I9 comprises a film of-titanium or other photo-sensitive ma 'terial, as in the preceding embodiment. Such a film is desirably deposited upon an electrical conductor preferably formed of a sheet of nickel I5, which is electrically connected teIeading-in conductor 20*, passing through a eal II! in the side of the envelope I2, through supporting wiresfll and 22, the upper ends of which are apertured ,'asindicated at H8 and Us, to receive 'a pivot wire or. axle I2I secured to the cathode plat I9 and having a counterweight I22 secured Ltheretma's by means of awire'connector I23,'the

,endsof whi chare respectively welded to said counterweight and axle.- -One end of the axle I2 I desirably has angularlugsln'and I30 welded thereto, asshown in Figure 9, to facilitate p0 sitioning the parts by preventing more than of rotation. This manner of supporting the cathode-plate If9f- 'makes it possible to reverse its position by reversing the position of the envelope I2 a the counterweight I22 isheavy enough to overbalance'the plate I9; The plate is shown locked in its operative position in-Figures G and;

and unlockedin position to be activated in Fig; ure 8.

The electrode to function as an anode for association with the cathode I9 is, in the present embodiment, formed as a pair of arc-shaped fine wires 54 and 55 with their ends supported from the upper arc-shaped members I24 and I25 which, in turn, have their adjacent ends supported respectively on U-shaped longitudinally extending wire members I26 and I 21, which function asresistance in circuit with, the members I24 and I25 and prevent overheating during treatment, the lower or uniting portions of which project from support wires 58 and 59 extending from the press I3 and at least one connecting with lead I53 extending through said press.

In order to protect the light-transmitting semispherical end portion 84 of the envelopev from an obscuring deposit during activation of the cathode, by sputtering from the electrode I I as described in connection with the preceding embodiment, for example, a generally cylindrical shield I28 is provided having metal loops I29-and I39 on the sides thereof, allowing it to slide along the support wire 2I and 22 from the position shown in Figure 6 to a lower position, permitting rotation of the cathode I9 Said shield I 28 may be locked in uppermost position, as shown in Figures 6 and 7, when the cathode Ii! is in operative position, by means of a resilient latch member I3I, the upper portion of which is secured as by welding to a metal ring I32 fastened to the sup-' ports 2W and 22 adjacent'their upper ends but below the apertures I I8 and I I9, said latch carrying an iron armature I33 and a prong I34, which latter element fits in a corresponding aperture in a keeper member I35 on the cylindrical shield I28 for holding it in uppermost position until released by action of an external magnet, corresponding to the magnet 45 of the preceding embodiment, on the armature I33 to withdraw the prong I34 from the keeper I35 and permit the shield I28 to descend and release the cathode Iii for swinging to the desired position.

The support wires 58 and 59 also carry shield members I36 and I31 for shading the press I3 like the shield I4 of the preceding embodiment.

The phototube of the present embodiment may otherwise be manufactured like that of the preceding embodiment, that is, the sensitized cathode surface 3P is applied like the surface 3I of the preceding embodiment, when device is reversed and the cathode swung to the unlocked position shown in Figure 8, fromthe activating electrode I 4 as by electrical bombardment therebetween on direct current, with the electrode I I functioning as a cathode.

When sufliciently activated, the device is turned to the normal position shown in Figures 6 and 7, the shield I28 allowed to slide down to its lowest position represented by the dotted line I20, and the cathode I9 reversed to the position shown in said figures. The shield may then bereturned to the locked position illustrated in Figures 6 and 7, in accordance with the fol.- lowing procedure. The tube is turned on its side and inclined at an angle, with the top pointing diagonally upward. Byrevolving the tube on its axis the plate I9 can be made to swing around, due tothe counterweight I22, until it faces the top. If the tube is now maneuvered properly the lug- I20 or I will prevent the plate from swinging any farther even when the tube is tipped at an angle with its top pointing diagonally down.-

sfa.

ward.- In this position, the shield I28 can be tapped or worked down to engage the plate,and finally locked in the position shown in Figures 6 and 7. A slightly difierent but similar procedure will also place the plate I 9 and the shield I28 in the position shown in Figure 8. The phototube maybe employed like the phototube I I of the preceding embodiment, either with or without vacuum-enclosed relay tube and condenser connected to thelower or other'end portion of the envelope as in the preceding embodiment.

The stops I20 and I30Qmake it possible to conveni ently effect and control rotation of the oathode plate I9 The counterweight I22 may, if desired, be made of ma'gnetizable' material, such as iron or steel, for operation from the outside.

Aftergthe devices II and II are completely assembled and tested, the envelopes are desirably coveredwith light obscuring tape I38, except at the activeor convex ends 8-; and M as shown in Figure 10, and provided with operating cords and plugs I39 and I40. The film of activating material which forms'on the glass during the sputtering operation is desirably prevented 'from photo-emission during operation of the device by connection withthe anode, as by means of. a flexible wire I40 extending from an anode lead into engagementYwith thesputtered portion of the envelope, as shown in Figure 2. I

Although preferred embodiments of my invention have been disclosed, it will be understood that modifications may be made within the spirit and scope of the appended claims.

I claim: v

1. A photoelectric device comprisin an elongated envelope, one end of which is closed by an outwardly convex portion and the other by a flare tube, a plate electrode therein having a 0 flange extending from one surface thereof and formed withapertures, a pair of support. wires extending through saidape tures with their end portions at an angle to the main portions thereof, and connected by a stop for said plate electrode, an activating electrode in the form of a rod of photosensitive material extending generally parallel to said support wires and disposed inwardly thereof, an operating electrode beyond the angular ends of said support wires, and leadin conductors extending through said pressto said electrodes, whereby said movable electrode may be sensitized from saidactivatin electrode when swunginward and slid downward along its supporting wires, and then slid back to a position transverse to the axis of said envelope to face said operating electrode.

. 2. A photoelectric device comprising a generally cylindrical envelope, a movable plate electrode therein to act as a photosensitive cathode, support wires ,for said plate electrode, an activating electrode in the form of arod of photosensitive material extending generally parallel to said support wires andldisposed inwardly thereof, an operating electrode disposed therebeyond 3. A photoelectric device comprising an elongated envelope, ,one end of which is closed by an outwardly. convex portion, and the other by a flare tube, supportiwires extending longitudinally of said envelope toward said convex end portion, a plate electrode havingan' apertured flange extending from one surface thereof, a pair of said support wires extending through said apertures to their end portions at an angle to the main portions thereof, and connected by means forming a stop for said plate electrode, whereby the latter is swingable and slidable along said support wires, an operating electrode in the convex end portion of said envelope beyond the angular ends of said support wires, other support wires extending longitudinally of said envelope, the free ends of said other wires being connected by a generally circular bracing wire, said operating electrode being connected to said bracing wire, and lead-in conductors extending through said press to said electrodes.

4. A photoelectric device comprising an elongated envelope, one end of which is closed by an outwardly convex portion and the, other by a flare tube, support wires extending longitudinally of said envelope from said flare tube toward said convex end portion, a plate electrode having a flange formed with aperturesand flange extending from one surface thereof, a pairofi said support wires extending through said apertures with their end portions extending at an. angle to the main portions thereof, and connected by means of a bracing wire, another portion of. said plate electrode carrying, an outstanding flange with an edge portion notched forminea keeper, a resiliently mounted, latch member with a flanged end portion receivable in'said notch for looking said plate electrode in position, an operating electrode in the convex end portion of said envelope, and lead-in conductors extending through said press to said electrodes.

5. A photoelectric-device comprisihganflelon gated envelope, one end of which is closed by an outwardly convex portion and the'other by a flare tube, a collar gripping said flare tube; support wires extending from said collar longitudinally of said envelope toward said convex end portion, a plate electrode having a flange formed with apertures and flange extending from one surface thereof, a pair of said supportwires extending through said apertures, with their end portions at an angle to the main portions thereof, and connected by a wire forming a stop for said plate electrode, an operating electrode in the form of wires curved outwardly into the conex end ortion of said envelope beyond the angular ends of said support wires, and lead-in conductors extending through said press to said electrodes, whereby said movable electrode, may be sensitized when swung inward and slid downward along its supporting wires, and then slid back to a position transverse to the axis of said envelope to face said wire electrode for operation.

6. A photoelectric device comprising a generally cyl ndrical envelope, one end of which is closed by a generally hemispherical portion and the other by a flare tube providing a re-entrant portion terminating in a press, a collar gripping said flare tube, support wires extending from said collar longitudinally of said envelope toward said hemispherical end portion, a generally circular plate electrode having an apertured flange extending from one surface thereof, a pair of said support wires extending through said apertures with their end portions at an angle to the main portions thereof, and connected'by a wire forming a stop for said plateelectrode, an activating electrode in the form of a rod of photosensitive material extending generally parallel to said support wires and disposed inwardly thereof, an operating electrode in the form of wires curved outwardly into the spherical end portion of said envelope beyond the angular ends of said support wires, and lead-in conductors extending through said press to said electrodes, whereby said movable electrode may be sensitized from saidacti vating electrode when swung inward and slid downward along its supporting wires to face said activating electrode, and then slid back to a position transverse to the axis of said envelope'to face said wire electrode for operation.

7. A photoelectricdevice comprising a enerally cylindrical envelope, a movable plate electrode therein, an activating electrode, an operating electrode in the form of wires disposed outwardly thereof, and means supporting said operatin electrode comprising aflare tube terminating in an inwardly disposed press and closing one end of said envelope, support wires extending directly from said press and continuing longitudinally of said envelope, the free ends of said wires being connected by a generally circular bracing wire to which the ends of said electrode wires are 'secured.

8. A photoelectric device comprising a generally cylindrical envelope, a movable plate electrode therein, an activating electrode, an operating. electrode in the form of wires disposed outwardly thereof, means supporting said operating electrode comprising a flare tube terminating in an inwardly "disposed press and closing one end of said envelope, support wires extending directly from said press and continuing longitudinally of said envelope, the free ends of said wires bein connected by a generally circular bracing wire to which the ends of said electrode wires are secured, and aplate extending transverse to the axis of said envelope-and secured to said support wires between said activating electrode and bracing wire to shield the end portion of said envelope and contents from sputtered material.

9. Aphotoelectric device comprising a generally cylindrical envelope, a movable plate electrode therein, an activating electrode, an operating electrode in the form of wires disposed outwardly thereof, means supporting said operating electrode comprising a flare tube terminating in an inwardly disposed press and closing one end of said envelope, conductors extending from said press, support wires extending directly from said conductors longitudinally-of said envelope, the freeends of said wires being connected by a generally. circular bracing wire to which the ends of said electrode wires are secured, and a plate mounted on said leads for shadingsaid press from sputtered material.

10, .A photoelectric device comprising an elongated envelope, one end of which is closed by an outwardly convex portion, and the other by a flare tube, a collar gripping said flare tube, sup,- port wires extending from said collar longitudinally of said envelope toward said convex end portion, a plate electrode having an apertured flange extending from one surface thereof, a pair of, said support wires extending through said apertures with their end portions at an angle to the main portions thereof and connected by means forming a stop for said plate electrode, whereby the latter is swingable and slidable along saidsupport wires, an operating electrode in the form of wires curved outwardly into the convex end portion of said envelope beyond the angular ends of said support wires, other support wires extending from said press longitudinally of said envelope, the free ends of said other wires being connected by a generally circular bracing wire, said operating electrode wires having their ends connected to said bracing wire, and lead-in conductors extending through said press to said electrodes, whereby said movable electrode may be sensitized when swung inward and slid downward along its supporting wires and then slid back to a position transverse to the axis of said envelope and encircled by'said bracing wire to face the curved electrode wires for cooperation therewith.

11. A photoelectric device comprising an elongated envelope, one end of which is closed by an outwardly convex portion and the other by a flare tube, a collar gripping said flare tube, support wires extending from said collar longitudinally of said envelope toward said convex end portion, a .plate electrode having a flange formed with apertures and flange extending from one surface thereof, a pair of said support wires extending through said apertures with their end portions extending at an angle to the main portions thereof and connected by means of a bracing wire, another portion of said plate electrode carrying an outstanding flange with an edge portion notched to form a keeper, a resiliently mounted latch member with a flanged end portion receivable in said notch for locking said plate electrode in position, an operating electrode in the form of wires in the convex end portion of said envelope, and lead-in conductors extending through said press to said electrodes, whereby said movable electrode may be sensitized when swung inward and slid downward along its supporting wires and then slid back to a position transverse to the axis of said envelope, where its keeper is engaged by said latch to hold in that position to face said wire electrode for operation.

12. A photoelectric device comprising a generally cylindrical envelope, a movable plate electrode therein, a resiliently mounted latch for holding said electrode in operative position, a magnetizable armature on said latch to allow it to be operated from outside said envelope, an operating electrode in the form of wires disposed outwardly of said plate electrode when the latter is in operative position and held by said latch, and means supporting said operating electrode comprising a flare tube terminating in an inwardly disposed press closing one end of said envelope, support wires extending directly from said press and continuing longitudinally of said envelope, the free ends of said wires being connected by curved bracing wire means to which the ends of said electrode wires are secured.

13. A photoelectric device comprising an envelope consisting of a main ortion defined at one end by a generally semi-spherical end portion and at the other by a flare tube terminating in a press, a neck portion extending beyond said flare tube, photoelectric elements supported from said press in said main portion, said elements comprising a movable plate electrode, a rod electrode adapted to activate said plate electrode when in one position to function as a cathode when moved to operative position adjacent said semi-spherical end portion, wires disposed in said spherical end portion to function as an anode with respect to said .plate electrode when in operative position, leads extending through said press and connected with said electrodes, the leads from other lead, a condenser and a relay tube mounted on another flare tube and electrically connected to said plate electrode by one of said springs, another of said springs being connected to a lead extending through said other flare tube, said springs allowing for connection outside of said extension and subsequent insertion therein, whereby after insertion said second-mentioned flare tube may hermetically seal the outer end of said extension.

14. A photoelectric device comprising an envelope, a plate electrode therein, supporting means for said electrode, means pivoting said plate electrode to said supporting means, said plate electrode also having a counterweight for swinging it through 180 about said pivoting means, an activating electrode in said envelope, a shield mounted and longitudinally movable in said envelope for housing or exposing said activating electrode, an operating electrode disposed in said envelope outwardly of said pivoted electrode to function as an anode with respect thereto, and means in said envelope for locking said shield in position adjacent said pivoted electrode to hold it with one side or the other facing said operating electrode.

15. A photoelectric device comprising an envelope, a plate electrode therein and provided with pivoting means extending-therefrom, supporting wires mounted in said envelope and receiving said means for pivotally supporting said plate electrode, said plate electrode also having a counterweight for swinging it through 180 about said pivoting means, an activating electrode in said envelope, a generally cylindrical shield slidable on said supporting wires for housing said activating electrode, other support wires in said envelope extending outside of said'shield and terminating in arc-shaped bracing wires extending across said envelope, fine wires curved longitudinally from said bracing wires and lying in said envelope outwardly of said pivoted electrode to function as an anode with respect thereto, and means in said envelope for locking said shield in position adjacent said pivoted electrode so as to hold it with one side or the other facing said fine wires.

16. A photoelectric device comprising an envelope consisting of a main portion and another portion, a cathode disposed in said main portion and sensitive to radiations to be measured, anode 1 xinterior threads, said socket being protected by a tubular extension beyond said seal, and a conductor having an end portion provided with 'exterior threads fitting the threaded socket.

DONALD E. HENRY. 

